Bone development shows certain regularity with age. The regularity can be used to infer age and serve many fields such as justice, medicine, archaeology, etc. As a non-invasive evaluation method of the epiphyseal development stage, MRI is widely used in living age estimation. In recent years, the rapid development of machine learning has significantly improved the effectiveness and reliability of living age estimation, which is one of the main development directions of current research. This paper summarizes the analysis methods of age estimation by knee joint MRI, introduces the current research trends, and future application trend.
Epiphyses/diagnostic imaging* ; Age Determination by Skeleton/methods* ; Reproducibility of Results ; Magnetic Resonance Imaging/methods* ; Knee Joint/diagnostic imaging*

OBJECTIVE: To compare the effects of different concentrations of linolenin on inhibiting apoptosis of chondrocytes in the growth plate, and to screen the optimal concentration of linolenin, so as to provide theoretical support for delaying epiphyseal closure and promoting long bone growth in rats. METHODS: Two 4-week-old male SD rats (SPF grade) with a body mass of 80 g were selected. The growth plate cartilage of rat tibia and femur was dissected and isolated in vitro to obtain growth plate chondrocytes for culture. The chondrocytes were observed and identified by inverted phase contrast microscope and typeⅡ collagen immunofluorescence test, and then 20 ng/ml IL-1β was used to induce apoptosis of growth plate chondrocytes as model group, and added with 1, 10, 20, 40 μM linolenin as the experimental group, and 5 μM letrozole as the positive control group. The cells were cultured for 24 and 48 hours respectively. The drug promoted cell proliferation was observed by MTT method, and the drug inhibited cell apoptosis was detected by flow cytometry. RESULTS: Contents 1, 10, 20, 40 μM could promote cell proliferation in varying degrees, and the principle was that the drug inhibits IL-1β induced chondrocyte apoptosis in the growth plate, and the optimal concentration of drugs to inhibit apoptosis was 20 μM. CONCLUSION The appropriate concentration of linseed lignans can significantly inhibit the apoptosis of chondrocytes in the growth plate of rats, and the optimal drug concentration is 20 μM. It provides possibility for delayed bone closure and longer growth time to promote bone growth during development.
Male ; Rats ; Animals ; Growth Plate ; Chondrocytes ; Flax ; Rats, Sprague-Dawley ; Apoptosis ; Lignans/pharmacology*

Child ; Epiphyses ; Fracture Fixation, Internal ; Humans ; Lower Extremity

Objective To develop mathematical models for skeletal age determination with multiple statistic method based on the correlation between age and the growth of the epiphysis of extremitas sternalis of clavicle in Shanxi adolescents. Methods The 562 Shanxi sternoclavicular joint samples （454 cases of modelling, 108 cases of external verification） were scanned by the thin-section computed tomography. After volume rendering was obtained, indicators such as area of epiphysis, area of metaphysis, longest diameter of epiphysis and longest diameter of metaphysis of both extremitas sternalis of clavicle were collected. Indicators such as the ratio of area of epiphysis to area of metaphysis, and the ratio of longest diameter of epiphysis to longest diameter of metaphysis of both sides were calculated. Then multiple linear regression and random forest discriminant models were used to build mathematical models for age determination of adolescents. Results The obtained indicators exhibited a strong correlation with age （r>0.85）. The multiple linear regression model for males and females （all 4 indicators entering the model） based on the ratio of longest diameter of epiphysis to longest diameter of metaphysis and the ratio of area of epiphysis to area of metaphysis had an internal validation accuracy rate （±1.0 year） of over 92% and 108 cases had an external validation accuracy rate of over 70% （±1.0 year）. The out of bag error rates of random forest discriminant models were less than 2% for people over 18.0 years old （≥18.0 years old） and under 18.0 years old. The external validation accuracy rates of the 108 cases were over 80%. Conclusion The regression and discriminant models established in this study have certain reliability and accuracy and can be used in age determination of Shanxi adolescents.
Adolescent ; Age Determination by Skeleton ; Clavicle/diagnostic imaging* ; Epiphyses/diagnostic imaging* ; Female ; Forensic Anthropology ; Humans ; Male ; Models, Theoretical ; Osteogenesis ; Reproducibility of Results

Linear growth occurs at the growth plate. Therefore, genetic defects that interfere with the normal function of the growth plate can cause linear growth disorders. Many genetic causes of growth disorders have already been identified in humans. However, recent genome-wide approaches have broadened our knowledge of the mechanisms of linear growth, not only providing novel monogenic causes of growth disorders but also revealing single nucleotide polymorphisms in genes that affect height in the general population. The genes identified as causative of linear growth disorders are heterogeneous, playing a role in various growth-regulating mechanisms including those involving the extracellular matrix, intracellular signaling, paracrine signaling, endocrine signaling, and epigenetic regulation. Understanding the underlying genetic defects in linear growth is important for clinicians and researchers in order to provide proper diagnoses, management, and genetic counseling, as well as to develop better treatment approaches for children with growth disorders.
Child ; Diagnosis ; Epigenomics ; Extracellular Matrix ; Genetic Counseling ; Genome-Wide Association Study ; Growth Disorders ; Growth Plate ; Humans ; Paracrine Communication ; Polymorphism, Single Nucleotide

BACKGROUND: Giant-cell tumor of bone (GCTB) is a locally aggressive primary benign tumor presenting as an expansile osteolytic lesion affecting the epiphysis of long bones. Denosumab halts the osteolysis by giant cells thereby downstaging the tumor, helping in performing less morbid procedures to remove the tumor. Our aim was to report the incidence of local recurrence (LR) in patients operated following neoadjuvant denosumab, to investigate factors associated with LR following extended curettage for GCTB, and to compare the postoperative functional and oncological outcome of patients operated with and without neoadjuvant denosumab. METHODS: A total of 123 patients with a mean age of 29.6 years undergoing extended curettage for GCTB were retrospectively divided into group 1 receiving neoadjuvant denosumab and group 2 operated without denosumab. The mean follow-up period was 35 months. The perioperative characteristics and outcome were compared between the two groups and the factors for LR of GCTB were analyzed. RESULTS: The incidence of LR among patients operated after neoadjuvant denosumab therapy was 42.8% and was significantly high compared to that in patients without denosumab (p < 0.001). On multivariate logistic regression analysis, use of denosumab as a neoadjuvant was the only factor independently associated with LR following surgery (p = 0.002). Patients treated with denosumab had a lower LR-free survival rate (log-rank, p = 0.018). CONCLUSIONS: Denosumab was independently associated with increased LR following surgery for GCTB. Denosumab has to be used cautiously in patients in whom the burden of downstaging the disease outweighs the possible chance of LR.
Curettage ; Denosumab ; Epiphyses ; Follow-Up Studies ; Giant Cell Tumors ; Giant Cells ; Humans ; Incidence ; Logistic Models ; Osteolysis ; Recurrence ; Retrospective Studies ; Survival Rate

BACKGROUND: Ganz surgical hip dislocation via a posterior (Kocher-Langenbeck) approach is a popular procedure in the management of femoroacetabular impingement (FAI). We report the results of surgery performed through an anterolateral (Watson-Jones) approach in the management of anterolateral FAI. METHODS: Twenty-one hips in 20 patients (mean age at the time of operation, 17.3 years) were treated surgically using an anterolateral approach: 12 hips with Legg-Calvé-Perthes disease, three septic hips, three hips with avascular necrosis (combined with slipped capital femoral epiphysis [SCFE], femoral neck fracture, and developmental dislocation of the hip), two hips with epiphyseal dysplasia, and one hip with SCFE. All patients had anterolateral FAI. Surgical hip dislocation was performed in four hips with trochanteric osteotomy. Combined osteotomies were for neck lengthening in 11 hips, varus or valgus osteotomy in the proximal femur in four hips, and pelvic osteotomy in four hips. Clinical results were evaluated using a modified Harris hip score (mHHS). RESULTS: Range of hip flexion and abduction showed statistically significant improvement after surgery; however, the improvement in mean mHHS was not statistically significant. CONCLUSIONS: An anterolateral approach can be used as an alternative to a posterior approach in the management of anterolateral FAI with or without hip dislocation while safely preserving the blood supply to the femoral head and allowing simultaneous procedures in the proximal femur.
Dislocations ; Femoracetabular Impingement ; Femoral Neck Fractures ; Femur ; Head ; Hip Dislocation ; Hip ; Humans ; Legg-Calve-Perthes Disease ; Neck ; Necrosis ; Osteotomy ; Slipped Capital Femoral Epiphyses

BACKGROUND: Prophylactic pinning of the uninvolved side after unilateral slipped capital femoral epiphysis (SCFE) is controversial. The alpha angle, a measurement of femoral head-neck aspherity, was proposed as a predictor of progression of contralateral SCFE with a treatment threshold of greater than 50.5°. The aim of this study was to evaluate its validity in our cohort of patients. METHODS: A retrospective review of a 10-year series of patients who presented with unilateral SCFE was conducted. Minimum follow-up duration to identify contralateral progression was 18 months. Age, sex, ethnicity, and endocrinopathies were noted. Alpha angle measurements of the unaffected hip were performed by two independent observers. The average values of measurements were used for analysis. Univariate and multivariate logistic regression analyses were performed to identify predictors of contralateral progression. A receiver operating characteristic (ROC) curve was generated. RESULTS: There were 43 patients with unilateral SCFE. Seven patients (16.3%) developed contralateral SCFE. There were 31 males (72.1%) and 12 females (27.9%). The mean duration from index surgery to contralateral fixation was 43.9 weeks (range, 16.2 to 77 weeks). The mean alpha angle was significantly higher in the patients with contralateral progression (mean, 50.7°; standard deviation [SD], 5.4°; range, 43.8° to 58.5°) than in the patients without progression (mean, 43.0°; SD, 4.2°; range, 33.0° to 52.5°; p < 0.001). The alpha angle was also identified as a statistically significant predictor of contralateral progression on multivariate analysis (p = 0.02). The intraclass correlation coefficient for interobserver reliability was moderately strong at 0.76 (95% confidence interval, 0.55 to 0.87). The area under the ROC curve was 0.88. The treatment threshold of 50.5° had a sensitivity of 0.43, specificity of 0.94, and number needed to treat (NNT) of 2.7. The ideal treatment threshold derived from the ROC curve was 49.0°, which had a sensitivity of 0.71, specificity of 0.89, and an NNT of 1.7. CONCLUSIONS: Alpha angle is a potential predictor of contralateral hip involvement in children with SCFE who may benefit from prophylactic hip fixation. Results from our series suggest a treatment threshold be 49.0°. However, given the limited sample size and moderately strong interobserver reliability, larger studies are needed to validate our findings.
Asian Continental Ancestry Group ; Child ; Cohort Studies ; Female ; Follow-Up Studies ; Hip ; Humans ; Logistic Models ; Male ; Multivariate Analysis ; Retrospective Studies ; ROC Curve ; Sample Size ; Sensitivity and Specificity ; Slipped Capital Femoral Epiphyses

BACKGROUND AND OBJECTIVES: Mesenchymal stem cells (MSCs) become hypertrophic in long term despite chondrogenic differentiation following the pathway of growth plate chondrocytes. This terminal differentiation leads to phenotypically unstable cartilage and was mirrored in vitro by addition of hypertrophy inducing medium. We investigated how intrinsic TGF-β signaling is altered in pro-hypertrophic conditions. METHODS AND RESULTS: Human bone marrow derived MSC were chondrogenically differentiated in 3D culture. At day 14 medium conditions were changed to 1. pro-hypertrophic by addition of T3 and withdrawal of TGF-β and dexamethasone 2. pro-hypertrophic by addition of BMP 4 and withdrawal of TGF-β and dexamethasone and 3. kept in prochondrogenic medium conditions. All groups were treated with and without TGFβ-type-1-receptor inhibitor SB431542 from day 14 on. Aggregates were harvested for histo- and immunohistological analysis at d14 and d28, for gene expression analysis (rt-PCR) on d1, d3, d7, d14, d17, d21 and d28 and for Western blot analysis on d21 and d28. Induction of hypertrophy was achieved in the pro-hypertrophic groups while expression of TGFβ-type-1- and 2-receptor and Sox 9 were significantly downregulated compared to pro-chondrogenic conditions. Western blotting showed reduced phosphorylation of Smad 2 and 3 in hypertrophic samples, reduced TGF-β-1 receptor proteins and reduced SOX 9. Addition of SB431542 did not initiate hypertrophy under pro-chondrogenic conditions, but was capable of enhancing hypertrophy when applied simultaneously with BMP-4. CONCLUSIONS: Our results suggest that the enhancement of hypertrophy in this model is a result of both activation of pro-hypertrophic BMP signaling and reduction of anti-hypertrophic TGFβ signaling.
Blotting, Western ; Bone Marrow ; Cartilage ; Chondrocytes ; Chondrogenesis ; Dexamethasone ; Down-Regulation ; Gene Expression ; Growth Plate ; Humans ; Hypertrophy ; In Vitro Techniques ; Mesenchymal Stromal Cells ; Phosphorylation

Avascular necrosis (AVN) is defined as the cellular death of bone and bone marrow components due to the loss of blood supply, and associated with post-traumatic or non-traumatic events. AVN usually involves the epiphysis of a long bone, such as the femoral and humeral heads, which are susceptible to osteonecrosis. Many studies have been conducted but they were restricted to investigations of femoral head avascular necrosis. The presence of osteonecrosis in the proximal femur may impair biological fixation after total hip arthroplasty. We report a 56-year-old male patient with avascular necrosis located not only at the femoral head, but also in the entire femur, including the medullary cavity, who underwent total hip arthroplasty 2 years earlier along with a review of the relevant literature.
Arthroplasty, Replacement, Hip ; Bone Marrow ; Epiphyses ; Femur ; Head ; Humans ; Humeral Head ; Male ; Middle Aged ; Necrosis ; Osteonecrosis